Reversible hydraulic apparatus



Oct. 22, 1968 J. DUPORT ETAL REVERSIBLE HYDRAULIC APPARATUS OriginalFiled Jan. 17.7 1964 3 Sheets-Sheet l.

INVENTORS Oct. 22, 1968 J. DUPORT ET AL REVERSIBLE HYDRAULIC APPARATUSOriginal Filed Jan. 17. 1964 3 Sheets-Sheet 2 INVENTORS JACQUES DUPORTGILBERT MARI IN ATTORNEYS Oct. 22, 1968 J, DUPORT ETAL 3,406,632

REVERSIBLE HYDRAULIC APPARATUS Original Filed Jan. 17, 1964 3Sheets-Sheet 5 INVENTORS JACQUES DUPORT' GILBERT MART/N BY A, MA

ATTORNEYS United States Patent 4 9 Claims. c1. 103 3 ABSTRACT THEDISCLOSURE Reversible hydraulic apparatus composed of a duct having endportions capable of functioning either as inlets or outlets and having ahydraulic machine centrally located therein between two streamlinecasings which form with the duct, annular flow passages on either sideof the hydraulic machine. The casings are supported on the duct by twogroups of vanes; the hydraulic machine, casings and vanes beingsymmetrically arranged relative to a plane perpendicular to andintersecting a point on the longitudinal central axis of the duct. Thevanes in each group are inclined radially adjacent to the hydraulicmachine and the inclined portions of one group of vanes being similar tothe inclined portions of the other group of vanes and such that thevanes in each group can without change operate alternately as upstreamvanes for one direction of fluid flow and as downstream vanes for theother direction of fluid flow and can impart to the fluid flow whenoperating as upstream vanes a swirl varying in intensity across the ductpassage.

This application is a continuation application of application 338,522filed Ian. 17, 1964, now abandoned.

The present invention relates to improvements in that type of hydraulicapparatus which employs two directions of flow in their use, such ashydraulic installations comprising rotating hydraulic machines, pumps,turbines and turbine-pumps of the propeller or Kaplan type, which areutilized with two directions of flow so that they will operateidentically in either of two flow directions. Specifically, apparatusembodying the invention can be employed to advantage, for example, as ahydrojet for propelling or steering a vessel, in which use it isdesirable to generate an adjustable and reversible fluid flow such aswill cause the jet action to vary continuously, and sometimes rapidly,through a range up to and including a complete reversal of the forceproduced.

The primary purpose of the present invention is to provide improvedreversible hydraulic apparatus which is capable of changing from onedirection of flow to the other, rapidly and in continuous variation, orprogressively, without producing abnormal forces such as would causedamage to the machinery, or dangerous hydraulic phenomena, such as forexample, cavitation.

Conventional devices heretofore employed for the aforesaid purpose relyon pumps which are either able to generate flow in only a singledirection, or if capable of pumping in both directions, do so to thedetriment of their energy or discharge characteristics. In the case ofsingleway flow pumps, the only known methods of reversing jet reactionare either by duplicating the mstallation (one for each direction), orby providlng gating arrangements capable of directing the flow to therequisite orifices, or by the employment of jet deflectors. Thesemethods require bulky complicated equipment and are often diflicult toreconcile with satisfactory performance from the energy point of view.

3,406,532 Patented Oct. 1968 The present invention enables thedirectional reversal of the jet to be obtained under the best possibleoperating conditions without the employment of expensive or complicatedmechanisms. Hydrojets embodying the invention are not only capable ofpropelling and steering vessels, but can be utilized to stablizepitching, rolling andyawing, and to provide an adequate means ofcontrolling the immersion of underwater vessels or platforms.

In a reversible hydraulic apparatus made in accordance with theinvention, the entire fluid circuit is designed to operate at highefficiencies and to produce a powerful thrust in either flow direction.The operation of such apparatus as a whole can be made perfectlysymmetrical, that is to say, capable of producing equal thrusts andworking at equal efficiencies in opposite flow directions. Its designalso enables continuous, and if necesary rapid, thrust variations to beachieved, ranging from maximum thrust in one direction, to maximumthrust in the opposite direction.

To accomplish the aforesaid purposes, the hydraulic duct of an apparatusembodying the invention comprises the following basic components:

(a) Two orifices facing in opposite directions and each capable ofworking both as an inlet orifice and as a discharge orifice at theoutlet. When the apparatus is to be employed as a hydrojet the twoorifices are each shaped to ensure a total absence of fluid breakawaywhen employed as an inlet, and when discharging as an outlet, to causethe fluid to break away cleanly and form a drowned jet outwardly from apredetermined cross-section thereof. 4

(b) A single or multi-stage axial pump with impeller bladings and guidevanes symmetrically shaped, or with symmetrical blading pitch controlarrangements, ensuring identical pump characteristics in both flowdirections The pump is connected to the aforesaid inlet and dischargeorifices by ducts, the shape and length of which may depend onrequirements arising from the installation of the apparatus. These ductsshould always be designed to provide for the lowest possible loss ofhead in order neither to upset the velocity and pressure distribution atthe pump intake, nor to cause swirl or to interfere in any way with flowconditions in the discharge, especially in the case of hydrojets.

Reversal of the direction of fluid flow may be achieved in any one ofthe following manners, or by a combination of the same;

(1) By reversing the direction of rotation of the pump motor. When thismethod is employed, the pump impeller blading may remain at the sameangular blade position.

(2) By controlling the angular positions of the pump impeller blading.With this method ,the pump motor may have a single direction ofrotation. Y

Examples of some of the possible forms of apparatus by which theinvention may be practiced are hereinafter described more fully and areillustrated in the drawings, in which FIG. 1 is a schematic verticalsectional view of reversible hydraulic apparatus embodying the inventionand illustrates the manner in which such apparatus may be utilized as ahydrojet in a ship;

FIG. 2 is an enlarged detailed view of one of the inlet and dischargeorifices shown in FIG. 1;

FIG. 3 is a horizontal sectional view showing an alternative form ofinlet and discharge orifice;

FIG. 4 is a longitudinal or vertical sectional view of the centralportion of a reversible axial pump constituted to accomplish thrustreversal by reversing the direction of rotation of the pump, and ifnecessary, to accomplish thrust variation by controlling the pump motorspeech FIG. 5 is a vertical sectional view of the impeller blade shownin FIG. 4, the distance away from the impeller hub periphery;

FIG. 6 is a view similar to FIG. 5 but showing a section taken near theblade tip;

FIG. 7 is a view similar to that of FIG. 4 of areversible axial pumpconstructed to accomplish thrust reversal, and if need be, thrustvariations, by variation of the angular blade position;

FIG. 8 is a vertical sectional view of the impeller blade shown in FIG.7, the section 'beingtaken a short distance away from the impeller hu'bperiphery; and i FIG. 9 is a view similar to FIG.'8, but showing asection taken near the blade tip. V v

The hydrojet shown in FIG. 1 of the drawings is constructed and arrangedto produce a reaction force acting in either'direction'along thehorizontal axis X-X. The inlet and dischargeorifices '1 at the ends ofthe hydraulic ductof the hydrojet are positioned in the ships sides 2 asshown, and are connected to the pump casing 3 forming the centralportion of such duct by straight duct sections 4. The duct openingwithin the pump casing 3 is formed by the latter and the faired orstreamlined bulb casing 5 extending longitudinally centerally of suchpump casing and disposed on either side of the pump impeller 7. The bulbcasings 5 accommodate the pump motor or motors and the impeller bladingcontrol mechanism, and are attached to and supported within the pumpcasing 3 by a plurality of metal vanes 6 arranged around each bulbcasing. The vanes 6 both guide the flow of fluid through the duct,impart the necessary swirl to such fiow at the entrance to the impeller7, and then restore the flow so that it leaves the downstream vanes attheir original axial direction.

In designs in which thrust reversal is achieved by reversing the pumprotation as in the construction of FIG. 4, the whole hydraulic ductsystem comprising the impeller and bulb casings 3 and 5, respectively,is symmetrical with respect to a point on the pump axis XX. The groupsof guide vanes 6 around the bulb casings are positioned symmetricallywith respect to an axis through point 0. However, the guide vanespositions can be determined by adding a suitable rotation about the pumpaxis XX. In this type of design, the pump impeller 7 is of the propellertype; a special feature of each blade being that its axis of symmetry isperpendicular to the axis of rotation XX and that these two axesintersect at the above designated point 0 as well hereinafter becomemore clear. Where the blade angle is adjustable, the axis of symmetry ofa blade coincides with its swivelling axis.

In designs in which thrust reversal is achieved by reversing theimpeller blading, as in the construction of FIG. 7, the entire hydraulicduct system comprising the pump and bulb casings 3 and 5, respectivelyand guide vanes 6, is symmetrical with respect to a plane passingthrough the point 0 perpendicularly to the pump axis XX and indicated bythe line II in FIG. 1 (the guide vanes can however, be determined byadding a suitable rotation about XX to this symmetry). The guide vanesaround each bulb casing 5 however, are symmetrically arranged about thepump axis XX. In this type of design pump impeller 7 is also of thepropeller pump type; a special feature of each impeller blade being thatits swivelling axis lies within its plane of symmetry, as willhereinafter become more clear. The extreme positions at which the bladescan 'be set by means of the control system are symmetrical with respectto the plane containing the line I-I.

FIG. 2 of the drawings shows in detailed outline the formation of theinlet and discharge orifices 1 embodied in the construction of FIG. 1.As shown, the orifice 1 has the form of a symmetrical solid ofrevolution about the pump axis XX. Except where the orifice 1 joins theduct 4, its surface of revolution 8 diverges outwardly at acomparatively wide angle a, at least from the X-X axis. The transitionof the surface of revolution 8 section being taken a short I from thisangle to its juncture with the duct 4 takes the form of a radius I",which is small compared to the diameter of duct 4 e.g. no more thanone-quarter of this diameter. This construction prevents breakaway whenthe flow is into the orifice i.e., from left to right as viewed in FIG.2, and when the flow is in the opposite direction as indicated by thearrow in FIG. 2, such construction causes the w to break away cleanly soas to produce a discharging jet 9 of practically the same diameter asthat of the adjoining end of'the duct 4." 1

FIG. 3 of the drawings shows a modified form of inlet and dischargeorifice .embodying the invention In the construction of FIG. 3, thehydrojet duct sections 4 are connected to 'inturned flanges 1' formingthe openings in the ships hull 2, and such openings are provided withbars 10 forming a-screen across them to. keep for: eign bodies out ofthehydrojet. The shape ofthe transition from the duct wall 4 to theexteriorof the hull plating 2, and the cross-sectional shape 0f bars.10, are such as to prevent breakaway in the inflow 1.e., fromtop tobottom as viewed in FIG. 3. To achieve th s, the screen barcross-sections are made symmetrical with respect to their mean chord,with their widest part well towards the outside of the hull (see FIG.3). Thus, such an orifice discharging outwardly, the hydraul c passagesbetween adjacent bars and between the end bars and the transition fromduct to hull plating, will diverge sufliciently to ensure clean jetbreakaway practically as soon as the flow passes the widest part of thebar crosssection.

As previously indicated, FIG. 4 of the drawings shows the centralportion of a hydraulic structure such as illustrated generally in FIG.1, but constructed so that the flow reversal, and if necessary, fiowvariatlons, are achieved by reversing the direction of rotatlon of thepump and by controlling its speed.

As in the construction of FIG. 1, the reversible hydraulic apparatus ofFIG. 4 includes a centrally located pump casing 3 containing an impeller11 1ntermediate the symmetricalbulb casings 5 whlch are supported withinsuch casing by the guide vanes 6. For the sake of clearness, only oneguide vane is shown in detail on each side of the impeller, it beingunderstood that the guide vanes 6 associated with each bulb casmg 5 areof similar construction. The impeller pos1t10n is assumed to be suchthat the axis of symmetry, and possiblyialso the swiveling axis, of oneof the impeller blades is perpendicular to the plane of the dlagrarn;the point 0 in FIG. 4, which has been previously lndlcated to be thepredetermined centre of symmetry for the entire hydraulic duct system,being also the trace of th1s blade axis of symmetry. The construction ofone of the impeller blades is indicated by the lines 12, 13, 14 and 15;line 12 indicating the profile of the portion of the blade on theimpeller hub, line 13 showing the blade profile at its tip, and lines 14and 15 indicating the blade edges, which act either as leading ortrailing edges depending on the direction of pump rotation and thedirection of flow. The outlines of the two detailed guide vanes 6 inFIG. 4, which connect the bulb casings 5 to the inner wall of the pumpcasing 3 are shown by the lines designated 16, 17, 18 and 19. Thenumerals 16 and 17 indicate the inner and outer longitudinal edges,respectively, 'o the guide vanes; the inner lines 16 indicating theoutline of the guide vane at the bulb casing 5 and the outer lines 17indicating the outline of the guide vane at the inner wall of the bulbcasing 3. The numerals 18 and 19 indicate the inner and outer end edges,respectively, of the guide vanes, which end edges will act either asleading or trailing edges depending on the direction of flow of thefluid through the duct. Each guide vane has the general shape of a fin;the portion thereof which is positioned farthest from the impeller 11,extending in the general direction of a plane radial to the X-X axis orone parallel thereto, and the portion thereof which is positionednearest to the impeller 11, extending in a general direction inclinedwith respect to the XX axis. In the construction shown, the majorportion of each guide vane which is spaced farthest away from theimpeller, approximately follows a radial plane extending out from the XXaxis and perpendicular to the plane of the drawing, while the remainingportion of each vane adjacent to the impeller curves or inclines awayfrom the radial plane passing through the XX axis and through the linearor major portion of the vane. As the angle of inclination of suchremaining portion of the vane is more pronounced near the bulb casing 5than near the pump casing 3, the guide vanes upstream of the impeller inaddition to acting as distributor vanes, also impart to the fluid flow aswirl in the direction of pump rotation; the intensity of this swirlincreasing from the pump cas ing to the bulb casing. As has beenpreviously stated, the guide vanes 6 are evenly spaced about the XX axisof the machine and act both as distributor vanes and flow straighteners(depending on whether they are upstream or downstream of the impeller ina given operation), while also forming a rigid support between the bulbcasing 5 and the pump casing 3.

It has been previously pointed out that a special feature of theimpeller blades is that their axis of symmetry is both perpendicular toand intersects the XX axis of the machine. In the case of adjustableimpeller blades, the axis of symmetry of the blade also coincides withits swivelling axis. Another feature of these blades is their novelconfiguration which can best be demonstrated by considering straightcross-sections of these blades in planes perpendicular to the bladesymmetry and swivelling axis, it being assumed, in the case of anadjustable blade, that the blades are at their maximum angle ofinclination. Two such straight cross-sections are shown in FIGS. 5 and 6of the drawings. In FIG. 5, the line indicates the outline of a bladecross-section lying in a plane intersecting the axis of symmetry of theblade a short distance away from the impeller hub periphery. In FIG. 6,the line 21 indicates the outline of a crosssection of the blade lyingin a plane intersecting the axis of symmetry of the blade near the bladetip. Both of the cross-sections shown are aerofoil sections, and therespective centres of symmetry thereof are the traces of theirrespective axes of symmetry O on the corresponding cross-sectionalplanes. It will be noted that unlike the more conventional type ofaerofoil, which almost invariably features at least one sharp edge, theleading and trailing edges of these cross-sections are rounded-off. Themedians of these sections are in the general shape of a letter S withits point of infiexion coinciding with the centre of symmetry.

In the construction of blade considered to be suitable to inversablespeed pumps in accordance with the invention, the angle of inclinationof the blade profile medians with respect to a plane containing the lineI-I and perpenddicular to the XX axis and intersecting it at thepreviously defined centre of symmetry 0 increases towards the impellerhub. In other words, the impeller blades for such purpose are given atwisted shape to allow for the variable tangential fluid entrainmentvelocities along their leading and trailing edges.

In the aforesaid types of twisted blades, the range of angular bladetravel in the case of an adjustable blade should be such that the bladecan assume any position between zero incidence of its outer pro-file andthe maximum angle of inclination of that profile; the usual ranges beingsomewhere between 20 and It should also be noted that the special shapesof the above described blades are the result of the necessity ofachieving symmetrical operation of the hydraulic apparatus in bothdirections of pump rotation and flow In FIG. 7 of the drawings is showna view similar to FIG. 4 of a reversible axial pump constructed inaccordance with the invention, wherein the flow is controlled, andreversed, by reversing the pitch of the impeller blades as required. Ashas already been indicated, a single-speed or, if necessary, a variablespeed pump with a nonreversible direction of rotation is suitable forthis application. As in FIG. 4 the symmetrical bulb casings 5, the pumpcasing 3 and the impeller 11 of the construction of FIG. 7 are showngenerally and only one of the guide vanes 6 provided on each side of theimpeller is shown in detail. The impeller is shown with one of itsblades end-on, that is to say, with the blade swivelling axisperpendicular to the plane of the drawing and, as before, the trace ofthe intersection between axes XX and 1-1 is indicated by thepredetermined point 0. The line designated 22 indicates the outline ofthe blade at the impeller hub, and the line designated 23 indicates theprofile of the blade at its tip. The lines 24 and 25 designate the bladeleading and trailing edges respectively.

The outlines of the guide vanes at their connection to the respectivebulb casings 5 are indicated by the numerals 26, and the outlines ofsuch vanes at their connection to the pump casing 3 are indicated by thenumerals 27. The leading and trailing end edges of the guide vanes, or-vice-versa, depending on the direction of flow, are indicated by thenumerals 2S and 29. As in the construction of FIG. 4, the generaldirection of the guide vane end portions farthest away from the impellerin the construction of FIG. 7 is in a radial plane, or in one parallelto the XX axis; the positions of the guide vanes shown in the drawingsbeing such that the major portions of the vanes farthest away from theimpeller are disposed from the bulb casings roughly on a radius runningout from the XX axis and perpendicular to the plane of the drawings. Theshapes of the guide vanes in the construction of FIG. 7 are quitedifferent from those described in the embodiment of FIG. 4 in that,basically, the ends of the guide vanes nearest to the im-. peller aremore steeply inclined in the direction of impeller rotation near thepump casing 3 than they are at the bulb casing 5. As is illustrated inFIG. 7, in some layouts the inclination of the guide vane near the bulbcasing may even run contrary to the direction of rotation of theimpeller. It will also be noted in FIG. 7 that the angle of guide vaneinclination varies continuously from the impeller periphery towards thehub, in order to impart a swirl in the direction of impeller rotation tothe water when the guide vane is acting as a distributor vane. Thisswirl is most pronounced in the flow nearest the periphery, but may bereduced to zero or reversed near the hub.

It is to be pointed out that the basic feature of the impeller bladeshape in the construction of FIG. 7, is that the blade swivelling axislies in the blade plane of symmetry. This is illustrated more clearly inFIGS. 8 and 9 of the drawings which show cross-sectional outlines of theimpeller blade in planes perpendicular to the blade swivelling axis. Theoutline in FIG. 8 designated 30 is the outline of the bladecross-section taken perpendicularly to and intersecting the bladeswivelling axis at a point near the impeller hub. The outline in FIG. 9designated 31 is the outline of the blade cross-section which lies in aplane parallel to the above, but intersects the blade swivelling axisnear the blade tip. The lines J] and J'I in these two figures are thetraces of the plane of symmetry of the blade, in the above mentionedcross-sectional planes and are therefore parallel. They thus representthe axes of symmetry and the mean chords of the cross-sections 30 and31. Contrary to the blades in the embodiment of FIG. 4, the blades inthe construction of FIG. 7 are rounded-off at one end and sharp at theother; the former acting as the leading edge and the latter acting asthe trailing edge, irrespective of the direction of flow. It should alsobe noted that the thickness chord ratio of the profiles is substantiallyconstant, from the centre to the periphery of the blades.

In reversing the flow and thrust of the impeller blades in theconstruction of FIG. 7, they are swivelled to positions which aresymmetrical with respect to the said 7 plane indicated by the line I-Iof FIG. 1. Conventional control systems of the type used for Kaplanturbines or ships screws are suitable for operating these blades. Thetotal range of angular travel of the blades may range between 40 and 70(e.g. 20-35 to either side of the plane indicated by the line 1-1). Withthis arrangement the direction of the flow produced by a propeller pumpcan for example be reversed without reversing the direction of pumprotation, by swivelling each impeller blade so that the angles ofinclination with respect to the median plane of all of its profiles aresymmetrically opposite to those angles present when the blades are intheir original positions. Continuous thrust reversals can be achieved inthis way, as the angle of blade inclination will decrease progressivelybefore changing its sign. The'absence of blade twist in the bladesemployed in the construction of FIG. 7, also requires the type of flowstraightening and distribution vanes 6 described above, in order thatsuitable angles of incidence may be obtained on the impeller blades andguide vanes in both flow directions.

It will be understood from the foregoing, that the use of reversibleflow axial pumps embodying the invention and described above by way ofexample, are not restricted to hydrojets. These pumps can be used forany application requiring a reversible flow. It will also be understoodthat the special features described herein, especially where referringto symmetry of form, arrangement of impeller blades and guide vanes, andtheir mutual adaptation, can also be applied to axial or pump turbinesfor instance with a view to harnessing hydraulic power under reversibleheads. It is of course possible, with respect to reversible flow axialpumps embodying the invention to adjust the pump speed, and/or theblading angles, to obtain, at all times, the optimum operatingconditions. Accordingly, while we have herein described and illustratedin the drawings, examples of reversible hydraulic apparatus by which theinvention may be practiced, it will be understood that we do not intendto limit our invention to such examples but contemplate including allreversible hydraulic apparatus coming within the scope of the appendedclaims.

We claim:

1. Reversible hydraulic apparatus comprising an elongated dust having atits ends two orifices facing outwardly in opposite directions and havingend portions of such similar construction that each such duct endportion is capable of functioning as an inlet and as an outlet for fluidpassing therethrough, both of said duct end portions being constructedto insure a total absence of fluid breakaway when used as an inlet, andwhen used as an outlet to cause the fluid to break away cleanly anddischarge in the form of a jet, a hydraulic machine operable to causereversible hydraulic flows through said orifice and constituted of apump or turbine centrally located within said duct and having rotor vaneblades the profiles of which are symmetrical with respect to a planedefined by the cords of all the profile cross sections, this plane ofsymmetry containing the blade rotating axis, a pair of streamlinedcasing symmetrically disposed on both sides of said plane with saidhydraulic machine therebetween, said casings extending longitudinallycentrally of said duct between said orifices with their longitudinalcentral axes coinciding with the longitudinal central axis of said ductand their exterior surfaces forming with said duct annular flow passageson either side of said rotor, said rotor, casings and duct portionenclosing the same being symmetrically arranged with respect to saidpoint on the longitudinal central axis of said duct portion, and meansfor supporting each of said streamlined casings on the portion of theduct wall enclosing the same, said supporting means comprising aplurality of fixed vanes extending longitudinally in the annular flowpassage formed by said casings and duct wall portion and connected attheir outer longitudinal edges to the latter, each of said vanes havingan inclined portion adjacent to the rotor against which the fluid reactsduring its passage through the duct, said vanes being in two groups, oneof the groups thereof being on one side of said rotor, and the othergroup 'there-: of being on the other side of said rotor, andeach'of'such groups including a plurality of vanes arranged in spacedrelation around its associated casing and being substan-' tiallyradially disposed as a whole, said groups 'of vanes being symmetricallyspaced relative to said point so that the inclined profiles of the vanesin one group'are symmetrical with respect to the inclined profiles ofthe'vanes in the other group, the configuration of the vanesinboth'groups being such that the vanes in each gr'oupcan without changeoperate alternately as upstream vanes for one di rection of fluid flowand as downstream vanes for-the other direction or fluid fiow,'the'inclined portions of'the pluralityof vanes in both groups beingsubstantially sim ilar and varying radially from their associated casingto the duct wall, the inclination of such'inclined 'portions being suchthat the group of vanes upstream of the rotor-in the then fluid flowimparts to the fluid flow a'swirl.varying-:in intensity-across theassociated portion of the .duct passage, and: the group'of vanesdownstreamof the rotor in the then fluid flow causes the fluid flow tobe linear downstream'iof such downstream group of vanes: 2. Reversiblehydraulic apparatus such as definedzxin claim 1, in which each duct endportion is composed of a frusto-conically shaped wall divergingoutwardly at an angle greater than 20, said wall merging from such'angleat its inner reduced end into a wall portion defining-a divergingopening curved through va given radius.

3. Reversible hydraulic apparatuscomprising an elon-' gated duct havingat its ends two orifices facing outwardly in opposite directions andhaving end portions of suchsimilar construction so that each such ductend: portion is capable of functioning as an inlet and as an outlet forfluid passing therethrough, a hydraulic machine operable to causereversible hydraulic flows through said orifices and constituted by apump or turbine centrally located within said duct and having a hub androtor blading the profiles of which are symmetrical with respect to aplane defined by the chords of all the profile cross sections,.thisplane of symmetry containing the blade rotating axis, said rotor bladingbeing adjustable and constructed toreverse the direction of fluid flowwhile maintaining one direction of rotation, a pair of streamlinedcasings symmetrically disposed on both sides of said rotational axiswith said hydraulic machine therebetween, said casings extendinglongitudinally centrally of said duct between said ori fices with theirlongitudinal central axis coinciding with the longitudinal central axisof said duct and'their exterior surfaces forming with said duct annularflow passages on either side of said rotor, and means for supportingeach of said streamlined casings on the portion of the duct wallenclosing the same, said supporting means comprising a group of vanesextending longitudinally in the annular flow passage formed by saidcasing and connected at their outer longitudinal edges to said ductwall,-said rotor hub,,vanes, casings and duct portion enclosing the samebeing symmetrical with respect to a plane passing perpendicularlythrough a point on the longitudinal central axis of said duct portion,said vanes in each group being substantially radially disposed as awhole and arranged in spaced relation around said casing, and each ofsaid, vanes constituting two distinct portions, a first portionextending linearly longitudinally of the flow passage and constituting thebody portion of the vane, and a second portion terminating in aninclined end portion adjacent to the rotor, said second end portions ofthe vanes in each group adjacent to said rotor and against which thefluid reacts during its passage through the duct, being annu-v larlyinclined to the body portions of such vanes and having an inclinationvariable radially from their associated casing to the duct wall, thesaid variably inclined end portions of the group of guide vanesassociated with one casing being substantially similar to the variablyinclined end portions of the group of guide vanes associated with theother casing, and the variable radial "inclination of the end portionsof the guide vanes in both groups being such that the vanes in eachgroup can without change operate alternately as upstream vanes for onedirection of fluid flow and as downstream vanes for the other directionof fluid flow and can impart to the fluid flow when operating asupstream vanes a swirl varying in intensity across the associatedportion of the duct passage.

4. Reversible hydraulic apparatus such as defined in claim 3, in whichthe inner end portions of said vanes are inclined at a greater anglenear said duct wall than near said casing so that the swirl in the fluidis more pronounced nearest the periphery of said duct passage.

5. Reversible hydraulic apparatus comprising an elongated duct having atits ends two orifices facing outwardly in opposite directions and havingend portions of such similar construction so that each such duct endportion is capable of functioning as an inlet and as an outlet for fluidpassing therethrough, a hydraulic machine operable to cause reversiblehydraulic flows through said orifices and constituted of a pump orturbine centrally located within said duct and having a hub andadjustable rotor vane blades constructed to reverse the direction offluid flow while maintaining one direction of rotation, said vane bladesbeing symmetrical relative to a straight plane at the midpoint of theaxial extremities of the rotor and perpendicular to and intersecting thelongitudinal central axis of said elongated duct, said blades having arounded leading edge and a relatively sharp trailing edge and theprofile of each blade being symmetrical with respect to a straight planedefined by the chords of the profile of all sections of the blade andcontaining the blade rotating axis, a pair of streamlined casingssymmetrically disposed on both sides of said straight plane with saidhydraulic machine therebetween, said casing extending longitudinallycentrally of said duct between said orifices with their longitudinalcentral axes coinciding with the longitudinal central axis of said ductand their exterior surfaces forming with said duct annular flow passageson either side of said rotor, and means for supporting each of saidstreamlined casings on the portion of the duct wall enclosing the same,said supporting means comprising a plurality of vanes extendinglongitudinally in the annular flow passage formed by said casings andduct wall portion and connected at their outer longitudinal edges to thelatter, said rotor hub, vanes, casings and duct portion enclosing thesame being symmetrical with respect to said straight plane, each of saidvanes having an inclined portion adjacent to the rotor against which thefluid reacts during its passage through the duct, and said vanes beingin two groups, one of the groups thereof being on one side of saidrotor, and the other group thereof being on the other side of saidrotor, and each of such groups including a plurality of vanes arrangedin spaced relation around its associated casing and being substantiallyradially disposed as a whole, the configuration of the vanes in bothgroups being such that the vanes in each group can without changeoperate alternately as upstream vanes for one direction of fluid flowand as downstream vanes for the other direction of fluid flow, theinclined portions of the plurality of vanes in the group upstream of therotor in the then fluid flow varying radially from their associatedcasing to the duct wall to impart to the fluid flow a swirl varying inintensity across the associated portion of the duct passage, and saidinclined portions being inclined at a greater angle near said duct wallthan near said associated casing so that the swirl in the fluid is morepronounced nearest the periphery of said duct passage, the inclinedportions of the plurality of vanes in the group downstream of the rotorin the then fluid flow varying radially from their associated casing tothe duct wall to impart to the fluid flow a swirl varying in intensityacross the associated portion of the duct passage, and said inclinedportions in such downstream vanes being inclined at a greater angle nearsaid duct wall than near said associated casing so that the flow islinear downstream of such downstream group of vanes.

6. Reversible hydraulic apparatus such as defined in claim 5, in whichthe inclination of the inner end portions of said vanes near said casingis counter to the direction of rotor rotation.

7. Reversible hydraulic apparatus such as defined in claim 5, in whichsaid blading is at the angular position of +13 for one direction offlow, and at the angular position of B for the other direction of flow,the construction of said blading being such that the thickness chordratio of the profiles is substantially constant from the center to theperiphery of said blading.

8. Reversible hydraulic apparatus as defined in claim 5, in which theinclination of the end portions of such vanes is such that that group ofvanes which is then upstream of the rotor imparts to the fluid flow aswirl in the direction of rotor rotation.

9. Reversible hydraulic apparatus comprising an elongated duct having atits ends two orifices facing outwardly in opposite directions and havingend portions of such similar construction so that each such duct endportion is capable of functioning as an inlet and as an outlet for fluidpassing therethrough, both of said duct end portions being constructedto insure a total absence of fluid breakaway when used as an inlet, andwhen used as an outlet to cause the fluid to break away cleanly anddischarge in the form of a jet, each of said orifices having a screen ofbars across the opening thereof, said bars having cross sectionssymmetrical with respect to a mean chord extending parallelly to thecentral axis of the associated duct end portion and of tear drop shapewith the widest part of said cross-section at the outer end of saidassociated duct end portion, and the surface portions of the outer endof said associated duct end portion in opposed relation to the outersides of the end bars in said screen having configurations comparable ofthe configurations of the latter, whereby the hydraulic passages formedbetween adjacent bars and between the end bars and said duct surfaceportions provide jet breakaway at the widest part of the barcross-sections, a hydraulic machine operable to cause reversiblehydraulic flows through said orifices and constituted by a pump orturbine centrally located within said duct and having rotor bladingarranged about an axis perpendicular to and intersecting the longitudinal central axis of said elongated duct, a pair of streamlinedcasings symmetrically disposed on both sides of said rotational axiswith said hydraulic machine therebetween, said casings extendinglongitudinally centrally of said duct between said orifices with theirlongitudinal central axis coinciding with the longitudinal central axisof said duct and their exterior surfaces forming with said duct annularflow passages on either side of said rotor, and means for supportingeach of said streamlined casings on the portion of the duct wallenclosing the same, said supporting means comprising a group of vanesextending longitudinally in the annular flow passage formed by saidcasing and connected at their outer longitudinal edges to said ductwall, said vanes in each group being substantially radially disposed asa whole and arranged in spaced relation around said casing, and each ofsaid vanes constituting two distinct portions, a first portion extendinglinearly longitudinally of the flow passage and constituting the bodyportion of the vane, and a second portion terminating in an inclined endportion adjacent to the rotor, said second end portions of the vanes ineach group adjacent to said rotor and against which the fluid reactsduring its passage through the duct, being angularly inclined to thebody portions of such vanes and having an inclination variable radiallyfrom their associated casing to the duct wall, the said variablyinclined end portions of the group of guide vanes associated with onecasing being substantially similar to the variably inclined end portionsof the group of guide vanes associated with the other casing, and thevariable radial inclination of the end portions of the guide vanes inboth groups being such that the vanes in each group can without changeoperate alternately as upstream vanes for one direction of fluid flowand as downstream vanes for the other direction of 2,219,499 10/1940Troller 230-120 fluid flow and can impart to the fluid flow whenoperating 2,260,169 10/ 1941 Couch 230--120 as upstream vanes a swirlvarying in intensity across the 2,895,667 7/1959 Stalker 230-420associated portion of the duct passage. 3,112,610 12/1963 Jerger 10394 XReferences Cited 5 FOREIGN PATENTS 348,032 5/1931 Great Britain.

UNITED STATES PATENTS 723,798 2/1955 Great Britain.

1,688,808 10/1928 Gill 23012O 1,958,145 5/1934 Jones 230120 WILLIAM L.'FREEH, Primary Examiner.

